HK1024661B

HK1024661B - Knife with at least one guard

Info

Publication number: HK1024661B
Application number: HK00103445.5A
Authority: HK
Inventors: Professor Berns Harald
Original assignee: Martor Kg
Priority date: 1998-06-11
Filing date: 2000-06-08
Publication date: 2002-12-13

Description

The invention relates to a knife with a protective component corresponding to the general concept of claim 1.

In the case of a knife of US 40 91 537 A, a guard pen extending parallel to the cutting edge of the blade with its centre of length and spring-loaded in its guard position has three axis areas: the front longer axis area of the guard pen has a medium diameter, the axis area following it behind it, the locking area, a small diameter and the rear axis area following the locking area has the largest diameter.

A latch, which is moved transversely along the centre axis of the guard, has a latch opening of such diameter that the latter can alternately enclose the guard at its front axis of medium diameter and at its guard at its rear axis of small diameter, but not at its rear axis of larger diameter.

The outwardly free area of the plate-shaped latch constitutes an operating button. If the latch opening is aligned with the latch opening of the guard pin and the latch is not operated, the guard pin is arrested in its forward guard position.

When the cutting operation is started by pressing the control button of the cutter according to US 40 91 537 A, the outer face of the guard pin will hit the cutting material, allowing the guard pin to move into the grip against the recoil of a screw spring.

However, the interaction of the front axial centre diameter guard area with the spring-loaded bar of the knife according to US 40 91 537 A may cause friction-induced delay or even a clamp when the guard is pushed.

A protective pin arrangement similar to the US 40 91 537 A knife is described in DE 81 19 855 U1 with the difference, however, that the sledge-type actuator is adjustable in the longitudinal direction of the knife in a reclining position. The familiar knife is considered to be in need of improvement in this respect because, if the sledge happens to be in its rear reclining position, the protective pin has to be accidentally moved into its release position. This may happen, for example, when a worker inserts the sledge into the pocket of the workhorse to lift an opening cardboard with both hands.

US 142 942 is a non-generic knife for edge-working of boot or shoe soles, in which a spring-loaded pen, placed along the back of the blade, is restrained by means of a pressure spring set outwards axially to the tip of the blade with its free end curved hook-like, which encircles the tip of the blade in the cutting position. In this cutting position, the spring-loaded pen is secured by means of a spring-loaded resting tip in the locking direction (see US 142 942 A Fig. 2 D, E, n). In the cutting position, the spring-loaded pen has a hook-like top end as a cutting edge, which is intended to prevent injury to the blade in the case of a cutting edge, in accordance with US 142 942 A.

In the case of a change or sharpening of the blade, the resting pin is removed so that the spring pin with its hooked area in front of the blade tip is moved forward (see US 142 942 A, Fig. 2).

A knife of the same type, according to DE 34 33 286 Al, is known to move a U-shaped protective part in the cross section longitudinally relative to a blade and to make this movement by means of an actuator.

Finally, DE 35 40 026 A1 is a knife with a self-propelled spring-loaded protective part, which is adjustable around a spindle, with a spring-loaded access. The protective position of the known rotating protective part is secured in a rather cumbersome manner by a separate handleable rotating safety handle.

According to the invention, this task is solved by a knife as described in claim 1.

According to the invention, a low pressure on the control button causes the protective part to be unlocked in its forward position so that, when the button is pressed, the protective part can be pushed back into its release position exposing the cutting edge.

According to the invention, the protective part, even when the control button is kept depressed and when cutting is interrupted or when cutting is completed, returns to its advanced protective position but subsequently remains in its stop position caused by the actuation stop device despite the actuation button being depressed.

The translated moving part may also be provided with a movement limitation to achieve a specified cutting depth, which may be changed either gradually or unsteadily (e.g. by means of a screw).

According to the invention, the translation direction of the pen area is in the plane of the swivel of the chisel or parallel to it.

An embodiment of the invention in which the crank is a drawbar crank has proved to be appropriate.

An advantageous embodiment of the invention is characterized by the fact that the control button is coupled to a control body which has a control surface with which the clamp can be pressurized in the unlocking direction.

The control surface is part of a control space, which allows the pin to penetrate in the direction of immersion with its head towards the tip of the knife while the pen is in its protective position. In order for the pin to perform its locking function in this position, i.e. to be able to penetrate the control surface with its control surface, the depth of immersion of the pin and the depth of immersion in the direction of the control space are coordinated.

A particularly advantageous embodiment of the invention also causes the pen area to stop in its protective position if the control button is still being operated by mistake after the cutting work has been completed and the pen area is thus relieved of pressure.

Such an advantageous embodiment is characterized by the fact that, according to the invention, the control body area constituting the control spring is confined in a limited, supple position relative to the control body in the direction of the plunge of the control spring in the direction of the plunge of the control spring, and that the supple position adjacent to the control spring forms a control head against which the control spring is running on its way from the release to the protection of the control spring, when the control spring is relieved of an external pressure and the control spring is operated in a sustained manner, the feedback of the control spring being applied as the force of the control spring, which is applied to the control spring by the pulling of the control spring towards the control spring.

The following additional subclaims are made for other features of the invention.

The drawings show examples of the invention. Fig. 1 a knife equipped as a sack opener before the cutting work begins,Fig. 2 a side view corresponding to the arrow of view designated by II in Fig. 1,Fig. 3 a front view corresponding to the arrow of view designated by III in Fig. 1,Fig. 1A the knife according to Fig. 1 when the cutting work begins,Fig. 4-6 different functional representations of another embodiment with open gripper interior andFig. 7-10 based on the representation according to Fig. 4-6 different functional representations of another embodiment.

The different embodiments shown and their individual parts are always designated with the same reference numbers, despite differences in design.

Each knife 10 has a handle 11 and a soluble blade 12 which is mounted on it, which is shaped as a trapezoidal blade in the examples shown and therefore has a straight cutting edge 13, a straight front face 14 inclined to the y-axis of the handle and a blade tip 15 in the front.

A safety bracket 16 has two parallel-spaced pins 17 whose internal ends 18 are approximately columnar in shape and are translatively mobile in a conduction channel 19 in exit position x and in exit position z.

The insertion of the pins 17 in the z direction is only possible against a spring-resistance force, which is generally indicated by a force vector F and, in addition, in Fig. 1 by a screw-pressure spring 20 with a dash.

In front of the pins 17 two leads 22 are connected to each other by a circular arc 21 and drawn around the blade 12 at a distance in front of the blade tip 15 and the forehead surface 14.

In particular, a comparison of Figures 1-3 and Figure 1A shows that the respective safety bracket 16 forms a protective space S on either side of the cutting edge 13 and in front of the blade tip 15 to accommodate the cutting edge 13 when the safety bracket 16 is in its forward protective position as shown in Figures 1-3, 4 and 5, Figures 7 and 8 and Figure 10.

In Figures 1-3 and 1A, the two leads 22 are joined by a backward-facing solder 25 each, with both leads 25 connected by a solder 24 in turn.

The function of all versions of the knife 10 is such that the knife 10 is placed on the sack surface E with the respective guide 22 of the safety brace 16 while the sack material 22 is sharpened and levelled between the two leads, as shown in particular in Figures 2 and 3.

Then the grip 11 is pushed downwards in the direction of pressure P, the safety grip 16 is inserted into the grip 11 along the slide z and the blade 12 penetrates the surface of the bag E. Then the cutting work can begin by moving the knife 10 in the direction of pressure A, cutting the bag.

All the embodiments shown have an actuator which can be operated by means of a control knob 27.

The first variant is that pressing the control button 27 causes the safety bracket 16 to unlock in its forward position (Fig. 1, Fig. 5) so that the safety bracket 16 can be pushed back in the z direction when the button 27 is pressed.

Once the button 27 is not pressed and the safety harness 16 has returned to its forward guard position (Fig. 1, Fig. 5), a stop shall automatically be initiated which will only allow the safety harness 16 to be pushed back in the z direction if the control button 27 is pressed.

An alternative embodiment is shown in Figures 7 to 10 in which, even if the button 27 is pressed continuously or continuously and (what is necessary) if the cutting work is interrupted or if the cutting work is finished, the safety brace 16 returns to its advanced protective position but then, despite the button being pressed (Fig. 10), remains in its stop position.

In accordance with the designs shown in Figures 5 to 10, the safety bracket 16 ends below its two pins 17 with the semi-circular arches 21, the guides 22, the free ends 23 and finally the bracket 24.

The conduction channels 19 for the two pin areas 17 divide into a conduction channel block 28 and an impact block 29.

At the upper ends of the pins 17 a bearing console 30 is fixed, which moves in the same direction as the pins in the x- and z-shaped positions.

At its free end, the bearing console 30 contains in a bearing bay 31 a drawbar K which is shaped like a double-arm lever and has a drawbar arm 32 with a drawbar head 33 and a back arm 34 which is back-loaded in the drawbar K by means of a pressure spring 35 in the input or locking direction by means of a drawbar 30 in the bearing console 30.

The pins 17 are shown in broken order to simplify the drawing, as is a draw spring 36 whose lower end is held in a hook 37 fixed to the handle and whose upper end is held in a hook 30 fixed to the bearing console 37A.

The control key 27, which has a control handle 38, is used to train a control body C in a single operation.

The control body C forms a control loop 39 with a control surface 40 which interacts with a counter control surface 41 at the crank head 33 of the crank K.

The clamp head 33 also forms a locking surface 42 designed to interact with the locking surface 43 of the locking block 29.

The function of the knife according to Figures 4-6 is as follows:

According to Fig. 4, the safety harness 16 is in its forward-locked position, the action harness, designated H, stops the safety harness 16 with its pin areas 17 in the position, because the locking surface 42 of the drawbar K locks the locking surface 43 of the drawbar 29 by locking it.

As soon as the control knob 27 is pressed against the backing force of the screw spring 44 with a pressure D and the steering body C is depressed, a release occurs between the locking surface 42 and the locking surface 43 (Figure 5).

Once the lock has been unlocked, the grip 11 can be pushed downwards in the direction of pressure P, while the safety grip 16 rests on the cutting material, namely on the sack surface E, so that the blade 15 can penetrate the sack surface E and start the cutting operation in the direction of cutting A.

From Figure 6 it can be seen that the K-clamp, together with the two pin areas 17, moved upwards relative to the grip 11

As soon as a work interruption occurs and the pressure P is removed, e.g. when the control button 27 is pressed, a reverse analogue movement is made from the state shown in Figure 5 to the state shown in Figure 4 in which the cutting position of the safety bracket 16 is arrested.

As can be seen by comparing Figures 5 and 4, the clamp head 33 is immersed in the control relief 39 with a dipping depth ET. The fact that the dipping depth ET is less than the depth AT of the control relief 39 ensures that, when the state described in Figure 5 is changed to the arresting state described in Figure 4, a seamless locking can be achieved between the clamp-side barrier 42 and the grip-resistant barrier 43

The above functional description also shows that it is sufficient to apply an initial pressure D and a simultaneous pressure P to move the safety lever 16 from its protective position (Fig. 4) to its release position (Fig. 6) to expose the cutter 13.

The form of the controller shown in Figures 7 to 10 differs from the form shown in Figures 4 to 6 in that the controller 39 in the output report x is only marginally flexible to the reserve power of a control spring 45 and is fitted with a single-arm lever 46 as part of the control body C, the rotary shaft 47 of which is adjacent to the control handle 38.

Between the control lever 39 and the rotary bearing 47, the single-arm lever 46 forms a control lever 48 pointing to the crank head 33.

The operation of the embodiment according to Figures 7-10 is as follows:

As shown in Fig. 7, the safety lever 16 is held in its protective position by means of the actuator H and is supported on the sack surface E. The locking surface 42 of the drawbar K is locked on the locking surface 43 of the actuator 29. As soon as the control handle 38 is pressed in the direction D against the recoil force of the screw spring 44, the control surface 40 of the control spring 39 of the single lever 46 presses the counter control surface 41 of the Klinik K and moves it into its position as shown in Fig. 8.

After the safety bracket 16 has been unlocked in accordance with Figure 8, a pressure P can be applied to the grip 11 in the same way as in Figures 5 and 6 and the cutting function can be achieved (see Figure 6).

Comparison of Figures 9 and 7 shows that the pin areas 17 and the drawbar K can move downwards in the direction of x when the control handle 38 is not actuated, and the same is done in the opposite direction, reaching the initial position as shown in Figure 7 without further delay, whereby a wedge-side slope 49 slides in the direction of x over a ramp surface 50 of the rigid attachment block 29 so that the drawbar head 33 can be brought into its resting position by the action of the screw-pressure spring 35.

The latter function applies even if the control button is not actuated for the previous example of operation when the position of Figure 6 is changed to the position of Figure 4.

However, if the pressure P is removed at the end of the cutting operation, but the control lever 38 is simultaneously pressurised with the pressure D, the condition as shown in Fig. 10 occurs, whereby the crank head 33 has previously run into the control spring 48 on its way to x. Since the spring's restraint force F is greater than the restraint force of the control spring 45, the spring 36 pulls the crank head 33 against the control spring 48 of the single lever 46, so that the latter is slanted downwards in the x direction and the crank head 33 is pushed back into its position as shown in Fig. 10 by the spring 35 unhindered.

Claims

Knife (10) with a safety guard (16), forming at least one rigid guard pin (17) which extends along the cutting edge (13) of a knife blade (12) and which is retained so as to be slidably displaceable parallel with its longitudinal mid-axis (L) in a slide guide compartment (19) of a handle body (11) and is able to slide from its safety position projecting beyond the cutting edge against the force of a spring return force (F) into a position in the handle body (11) in which the cutting edge (13) is exposed, the safety guard (16) co-operating with a lock operating mechanism (H) which can be both locked and released by means of an operating trigger (27) when the safety guard (16) is in the safety position, the safety guard (16) being locked in its safety position when the operating trigger (27) is not being operated, whereby the guard pin (17) is automatically returned from its release position to its safety position by the spring return force (F) and whereby the lock operating mechanism (H) has a lock stop surface (43) permanently joined to the handle body (11) and extending substantially transversely to the longitudinal mid-axis (L) of the pin region (17), characterised in that a lock is mounted on the guard pin (17) inside the handle body (11) which engages behind the lock stop surface (43) by means of a lock surface (42), thereby locking the guard pin (17) in its safety position, and in that the lock surface (42) can be displaced into the release position by means of the operating trigger (27), the lock being a catch (K) pivotably mounted on the guard pin (17), the control surface of which forms the lock surface (42).
Knife as claimed in claim 1, characterised in that the direction of translation (x, y) of the pin region (17) lies in the pivot plane of the catch (K) or is parallel therewith.
Knife as claimed in claim 1 or claim 2, characterised in that the catch (K) is a tension-operated catch.
Knife as claimed in one of claims 1 to 3, characterised in that the operating trigger (27) is displacingly coupled with a control body (C), which has a control surface (40), by means of which pressure can be applied to the catch (K) in the release direction.
Knife as claimed in claim 4, characterised in that the control surface (40) is part of a control recess (39) in which the catch (K) is downwardly inserted by its head (33) towards the knife tip (15), whilst the pin region (17) is located in its safety position, the insertion depth (ET) of the catch head (33) and the depth (AT) of the control recess (39) aligned with the insertion depth (ET) being designed to match one another.
Knife as claimed in one of claims 1 to 5, characterised in that the catch (K) is loaded in the locking direction (v), in particular is spring-biassed.
Knife as claimed in one of claims 4 to 6, characterised in that the control body (C) is return-spring-biassed on release of the catch (K).
Knife as claimed in one of claims 4 to 7, characterised in that the operating trigger (27) and the control body (C) are of an integral design.
Knife as claimed in one of claims 7 to 8, characterised in that the region (46) of the control body (C) forming the control recess (39) is mounted so as to be flexible to a restricted degree relative to the control body (C) in the downward direction in which the catch head (33) is inserted against the return force of a control spring (45), and in that the flexibly mounted region (46) forms a control projection adjacent to the control recess (39), against which the head (33) of the catch (K) runs on its travel from the release position to the safety position of the pin region (17) if external pressure on the pin region (17) is relaxed and the operating trigger (27) is continuously operated by an external pressure (P), the return force of the control spring (45) being lower than the spring return force (F) acting on the pin region (17), which opens the pivot path of the catch (K) to the lock stop surface (43) by displacing the flexible region (46).
Knife as claimed in claim 9, characterised in that the flexibly mounted region forms a single-arm lever (46).
Knife as claimed in claim 10, characterised in that the pivot bearing (47) of the single-arm lever (46) is adjacent to a control handle (38) of the operating trigger (27) and the control recess (39) is disposed on a longitudinal face on the free end of the single-arm lever (46) facing the catch head (33), whilst the control projection (48) located on the same longitudinal face is arranged between the control recess (39) and the pivot bearing (47).
Knife as claimed in claim 11, characterised in that the control spring (45) forming a compression spring on the longitudinal face of the single-arm lever (46) remote from the control recess (39) is arranged between the former and the control body (C).
Knife as claimed in one of claims 1 to 12, characterised in that the lock stop surface (43) attached to the handle body (11) is formed by a stop block (29) which simultaneously constitutes an axial guide (19) for at least one pin region (17).